The invention generally relates to construction tools for clamping together and relative spacial adjustment of building materials for their installation in the construction or remodeling of building structures. More specifically, the invention relates to pinch clamps which are driven into two pieces of building material to draw the pieces together allowing their proper attachment together or to a substrate.
In the construction and remodeling of building structures, such as houses or offices, many times two pieces of building materials need to be installed abutting one another. In many of these situations, using a traditional clamp (e.g., a pipe clamp), which grips the far edges of each piece of building material and forces the near edges together, is impractical or impossible. For example, when two boards are connected end to end, the combined length may be either too large for available traditional clamps or may make the use of traditional clamps excessively cumbersome for the installer. In addition, when attaching a piece of building material to another already installed piece, there may not be two opposite edges available for the traditional clamp to grips such as when assembling a countertop substrate.
The pinch clamp does not have these limitations. A pinch clamp is a small hand tool that has two prongs connected with a crossbar. An example of the prior art pinch clamp can be seen in FIGS. 1 and 2 (prior art). The prior art pinch clamp 10 has two prongs 12 connected by an elongated connecting bar 14. The prongs 12 are attached to the connecting bar 14 at a base 16 and have chisel edged tips 18 opposite the base 16. As can be seen in FIG. 2 (prior art), the chisel edged tips 18 of the prongs 12 do not come to a point but have a chisel edge 20. The prong 12 has inwardly tapered inner sides 22 and vertical outer sides 24. In practice, the chisel edged tips 18 of the pinch clamp are driven, usually by a hammer, into pieces of building material to be clamped. The hammer strikes the top prong end 26 of the connecting bar 14. If the hammer impacts the top middle portion 28 of the connecting bar 14, the connecting bar 14 may be bent and the pinch clamp 10 will no longer function properly.
Each prong 12 makes a hole in the building material by first inserting a chisel edged tip 18 into the building material and compressing the material surrounding the hole as the inwardly tapered inner side 22 and vertical outer side 24 are driven deeper. The inwardly tapered inner sides 22 of the prongs 12 force the two pieces of building materials together. The midpoint of the prong 12 between the inwardly tapered inner side 22 and the vertical outer side 24 is progressively closer to the center of the pinch clamp 10 along the connecting bar 14 the further up the prong 12 one gets from the chiseled edged tip 20. Since the building materials compress on both sides of each prong 12 and the midpoint of the prongs are closer to the middle of the pinch clamp 10 as the prongs are driven more deeply into the building materials, the two pieces of building material are thereby clamped together. The hole in the building material is usually filled or otherwise patched unless the building material is to be covered by another material.
While the prior art pinch clamp is widely used, it has several disadvantages. The connecting bar of the prior art pinch clamp may be bent if it is struck with the hammer in a place other than directly at a top end of the pinch clamp above one of the prongs. Further, the pinch clamp is narrow in width, making it easy to entirely miss the pinch clamp with the hammer or to drive the pinch clamp in at an angle other than the desired vertical. In addition, the prior art prongs must be driven rather deeply into the building material in order to cause a significant amount of relative movement or clamping force. Further, when the prior art clamp is driven deeply into the building material, it can be difficult to remove the pinch clamp without damaging the building material further or damaging the pinch clamp.
Therefore, it is an object of the invention to provide a pinch clamp which resists bending if struck other than directly above one of the prongs.
It is a still further object of the invention to provide a pinch clamp that provides increased clamping force compared to the prior art clamp when driven to the same depth in the building material.
A further object of the invention is to provide a pinch clamp that resists damage from a hammer blow to a portion of the pinch clamp other than directly over a prong.
A still further object of the invention is to provide a larger surface for being impacted with a hammer to ensure the pinch clamp is driven vertically into the building material.
A still further object of the invention is to provide a pinch clamp that can be more readily removed from the building material without damage to the pinch clamp or the building material.
The present invention achieves the above-described objects and advantages, and other objects and advantages which will become apparent from the description which follows, by providing a pinch clamp having two elongated, pyramidal prongs connected by a stiffening beam or connecting bar. Each prong has a triangular base connected to the distal ends of the stiffening beam, a distal pointed tip, an inner flat tapered side, and two outer sides defining a wedge shape. The base of the first prong is connected at its base to the first end of the connecting bar, and the base of the second prong is connected at its base to the second end of the connecting bar. The inner, flat, tapered sides of each prong face each other.
In the preferred embodiment of the present invention, the connecting bar has a top surface defining a transverse flange so that the connecting bar forms a stiffening xe2x80x9cTxe2x80x9d-shaped beam for resisting impact to the connecting bar, such as by a hammer. The preferred embodiment of the current invention also provides a knurled driving surface on each end of the connecting bar for impact by a hammer, allowing the inventive pinch clamp to be driven vertically into the building material. A further embodiment of the present invention comprises at least one removal flange at an end of the connecting bar allowing the removal of the inventive pinch clamp without damage to the pinch clamp or further damage to the building materials.